Why Some Braces "Work" Beyond Cobb Angle Correction: Hidden Dimensions of Treatment Effect

The Cobb angle remains the primary radiographic parameter for the assessment and management of adolescent idiopathic scoliosis (AIS), although it does not fully capture the multidimensional nature of the deformity or the broader impact of treatment. This narrative review aims to explore the mechanisms underlying brace effectiveness beyond coronal plane correction. Available evidence suggests that, in addition to three-dimensional structural correction, bracing may be associated with changes in postural control and sensorimotor function, likely related to altered loading conditions and sustained proprioceptive input. Brace treatment may also influence trunk balance and symmetry, contributing to perceived deformity correction and patient satisfaction independently of radiographic findings. Furthermore, the overall impact of bracing is reflected in patient-reported outcomes, including pain, function, and health-related quality of life, which do not necessarily correlate with changes in Cobb angle. These outcomes are closely shaped by psychological and behavioral factors, such as self-perception and treatment-related stress, which may influence adherence. Taken together, brace effectiveness should be understood as a multidimensional construct in which structural, functional, aesthetic, and patient-related factors interact. This perspective supports the need for comprehensive, multimodal assessment strategies in AIS management that extend beyond reliance on Cobb angle alone.